| circadian rhythm | The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs and stimuli, hormone secretion, sleeping, feeding, etc. This rhythm seems to be set by a 'biological clock' which seems to be set by recurring daylight and darkness. (12 Dec 1998) |
|---|---|
| circus rhythm | A contraction or excitation wave traveling continuously in circular fashion around a ring of muscle or through the wall of the heart. Synonym: circus rhythm. (05 Mar 2000) |
| coronary nodal rhythm | Formerly applied by some authorities to the electrocardiographic pattern of normal upright P waves in leads I and II with a short P-R interval. (05 Mar 2000) |
| coronary sinus rhythm | An ectopic atrial rhythm supposedly originating from a pacemaker at the mouth of the coronary sinus; recognised in the electrocardiogram by P-waves that are inverted in leads II, III, and a VI with a normal or prolonged P-R interval; an ectopic ("lower") atrial rhythm. (05 Mar 2000) |
| coupled rhythm | That cardiac rhythm when each beat of the dominant rhythm (sinus or other) is followed by a premature beat, with the result that the heartbeats occur in pairs (bigeminy). Synonym: coupled rhythm. (05 Mar 2000) |
| sinus rhythm | The normal regular cardiac rhythm stimulated by the sinoatrial node. (27 Sep 1997) |
| nodal rhythm | The cardiac rhythm when the heart is controlled by the A-V junction (including node); arising in the A-V junction, the impulse ascends to the atria and descends to the ventricles, each at varying speeds depending on site of the pacemaker. Synonym: A-V junctional rhythm, nodal bradycardia, nodal rhythm. (05 Mar 2000) |
| delta rhythm | Brain waves in the electroencephalogram which have a frequency below 3 1/2 per second. They are typical in deep sleep, in infancy, and in serious brain disorders. (12 Dec 1998) |
| systolic gallop rhythm | An obsolete term for extra sounds, usually clicks, heard during systole. (05 Mar 2000) |
| diurnal rhythm | Occurring during the day. (18 Nov 1997) |
| idiojunctional rhythm | An independent rhythm, the ventricles being under control of the A-V node (A-V junction). Synonym: idiojunctional rhythm. (05 Mar 2000) |
| idionodal rhythm | An independent rhythm, the ventricles being under control of the A-V node (A-V junction). Synonym: idiojunctional rhythm. (05 Mar 2000) |
| idioventricular rhythm | A slow independent ventricular rhythm under control of a ventricular centre (which is, by definition, ectopic). Synonym: ventricular rhythm. (05 Mar 2000) |
| quadrigeminal rhythm | A cardiac arrhythmia in which the heartbeats are grouped in fours, each usually composed of one sinus beat followed by three extrasystoles, but a repetitive group of four of any composition is quadrigeminal. Synonym: quadrigeminy. (05 Mar 2000) |
| quadruple rhythm | A quadruple cadence to the heart sounds due to the easy audibility of both third and fourth heart sounds, indicative of serious myocardial disease. Synonym: trainwheel rhythm. (05 Mar 2000) |